O-β-D-吡喃半乳糖基-(1→4)-O-β-D-吡喃半乳糖基-(1→4)-α-D-吡喃半乳糖苷丙酯的合成与表征

Synthesis and characterization of propyl O-beta-D-galactopyranosyl-(1----4)-O-beta-D-galactopyranosyl-(1----4)- alpha-D-galactopyranoside.

作者信息

El-Shenawy H A, Schuerch C

出版信息

Carbohydr Res. 1984 Aug 15;131(2):239-46. doi: 10.1016/0008-6215(84)85245-3.

Abstract

Allyl 4-O-(4-O-acetyl-2-O-benzoyl-3,6-di-O-benzyl-beta-D-galactopyranosyl)- 2-O-benzoyl-3,6-di-O-benzyl-alpha-D-galactopyranoside was O-deallylated to give the 1-hydroxy derivative, and this was converted into the corresponding 1-O-(N-phenylcarbamoyl) derivative, treatment of which with dry HCl produced the alpha-D-galactopyranosyl chloride. This was converted into the corresponding 2,2,2-trifluoroethanesulfonate, which was coupled to allyl 2-O-benzoyl-3,6-di-O-benzyl-alpha-D-galactopyranoside, to give crystalline allyl 4-O-[4-O-(4-O-acetyl-2-O-benzoyl-3,6-di-O-benzyl- beta-D-galactopyranosyl)-2-O-benzoyl-3,6-di-O-benzyl-beta-D-galactopyran osyl]- 2-O-benzoyl-3,6-di-O-benzyl-alpha-D-galactopyranoside (15) in 85% yield, no trace of the alpha anomer being found. The trisaccharide derivative 15 was de-esterified with 2% KCN in 95% ethanol, and the product O-debenzylated with H2-Pd, to give the unprotected trisaccharide. Alternative sequences are discussed.

摘要

烯丙基 4-O-(4-O-乙酰基-2-O-苯甲酰基-3,6-二-O-苄基-β-D-吡喃半乳糖基)-2-O-苯甲酰基-3,6-二-O-苄基-α-D-吡喃半乳糖苷经O-脱烯丙基化反应得到1-羟基衍生物，将其转化为相应的1-O-(N-苯基氨基甲酰基)衍生物，用干燥的HCl处理该衍生物得到α-D-吡喃半乳糖基氯。将其转化为相应的2,2,2-三氟乙烷磺酸酯，该酯与烯丙基 2-O-苯甲酰基-3,6-二-O-苄基-α-D-吡喃半乳糖苷偶联，得到结晶状的烯丙基 4-O-[4-O-(4-O-乙酰基-2-O-苯甲酰基-3,6-二-O-苄基-β-D-吡喃半乳糖基)-2-O-苯甲酰基-3,6-二-O-苄基-β-D-吡喃半乳糖基]-2-O-苯甲酰基-3,6-二-O-苄基-α-D-吡喃半乳糖苷(15)，产率为85%，未发现α异头物的痕迹。三糖衍生物15用95%乙醇中的2% KCN进行脱酯反应，产物用H2-Pd进行O-脱苄基化反应，得到未保护的三糖。还讨论了其他反应序列。